1. Field of the Invention
The present invention relates to an occupant weight detection system that includes a plurality of weight detection means for sharing detection of the weight of an occupant seated on a vehicle seat.
2. Description of the Related Art
Operation/non-operation of an airbag system for a passenger seat and variation of the deployment speed of an airbag, etc. are controlled according to the body size of an occupant seated on the passenger seat and whether or not an occupant is present, that is, according to the status. For example, control is carried out as follows: when the occupant is an adult or a child, the airbag system is operated, and when the occupant is an infant seated on a child seat or there is no occupant seated, the airbag system is not operated; furthermore, when the airbag system is operated, if the occupant is an adult the airbag is deployed at a high speed, and if the occupant is a child the airbag is deployed at a low speed. This enables the airbag system to exhibit a restraining performance that is optimum for the status of the occupant, thereby avoiding unnecessary deployment of the airbag.
An arrangement in which the above-mentioned status is determined based on the weight of an occupant detected by a single load cell provided in a seat is known from Japanese Patent Application Laid-open No. 11-94637. In this weight detection system, the weight of an occupant seated on the seat is applied to the single load cell via a link mechanism, thereby preventing the occurrence of detection error due to the posture of the occupant seated in the seat while minimizing the number of load cells.
The above-mentioned conventional arrangement has the problem that it is necessary to employ a complicated link mechanism in order to reduce the number of load cells to one; this problem can be solved by arranging weight detection units beneath left and right seat rails, and obtaining the weight of an occupant by adding the weights detected by the left and right weight detection units. However, when the left and right weight detection units are separate and are independently mounted on a vehicle body, it is difficult to maintain the precision with which they are mounted on the vehicle body, and there is a possibility that the left and right weight detection units might be twisted or displaced relative to each other, thereby affecting the detection accuracy.